Things to know about New Form Rendering Engine used by MS in CRM 2015 Update 1 and further

Things to know about New Form Rendering Engine used by MS in CRM 2015 Update 1 and furtherand impact of it on page load and custom javascripts and how to prevent issues in unsupported customization using custom code validation tool :

Microsoft Dynamics CRM Online 2015 Update 1 includes a number of terrific technical improvements including faster page loads, improved application performance, and faster email delivery. One noticeable feature is the new Form Rendering Engine. This enhancement loads CRM pages faster so you can view data on the forms quickly.

Users and administrators should be aware of the impact the new engine may have on their customizations and may need to consider enabling the “Legacy Form Rendering” setting if they encounter script errors due to the new form rendering engine. In today’s blog we will focus on the specifics of the new Form Rendering Engine and give you some tips and tricks for working with it! Let’s get started!

Here are a few of the benefits of the new Form Rendering Engine:

• No action is needed by users or administrator as this is turned on by default.
• The loading process for record forms is significantly better and faster since more content is cached. For more information on performance, see Microsoft’s note on form rendering engine.
• Common and custom scripts are handled separately.
• The engine has the same functionality as it is based on previous generations. It uses Form XML Schema and has full support for client scripting.

The tricky thing for users and administrators has to do with unsupported customization or direct DOM manipulations which will possibly fail and need to be re-engineered. The following are examples of when this might occur:

• Access window.parent from a web source that has to do with a variable set.
• Unsupported APIs, i.e., non-XRM.
• Window.load or iframe/form.
• Access DOM in content iframe using JQuery or JavaScript.

In order to help catch unsupported customization, MS has added a dialog that displays the issue when script errors occur so that they do not fail silently. If these symptoms occur then it is likely there are unsupported customization in the system.

We recommend formally testing any scripts, solutions, and customization in a sandbox to ensure proper functionality AS SOON AS POSSIBLE. To assist with testing and in order to prevent errors from going unnoticed, Microsoft has added a dialog box that will display the following error message should a script error occur:

The following two options are recommended when identifying potential issues:

• CRM 2015 custom code validator will identify usage of disapproved APIs as well as pursue to flag usage of APIs.

           Here is :how to use custom code validator 
            Download Microsoft Dynamics CRM 2015 Custom Code Validation Tool

• For those pesky issues that are difficult to pinpoint or that need a post-upgrade fallback plan, consider Legacy Form Rendering.

Under Settings -> System Settings -> General tab, select Yes for “Use legacy form rendering” as shown in the images below.

Note: this is a temporary measure, as this functionality is expected to be removed by Microsoft in the next CRM release. All the more reason to update any broken script immediately to avoid problems in the future.